First things first, this boxed set has four disks and not three, as the description claims (this may or may not be fixed by the time you read this).
It is the closest thing you will ever get to a complete collection of Jackass aired on television.
I'm not sure whether this boxed set contains everything Jackass has ever done (apart from the movie), but I can be certain that if it has missed anything out, then it wasn't anything important or particularly memorable. In fact, I'd wager the shirt off my back that you can't think of a stunt they did that isn't in this set.
Overall, as you'd expect, its classic Jackass all over - with plenty of stupid, weird and downright gross stuff from start to finish. Well worth the money.